Elliott Hughes | 2faa5f1 | 2012-01-30 14:42:07 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 16 | |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 17 | #include "mark_sweep.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 18 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 19 | #include <climits> |
| 20 | #include <vector> |
| 21 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 22 | #include "card_table.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 23 | #include "class_loader.h" |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 24 | #include "dex_cache.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 25 | #include "heap.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 26 | #include "indirect_reference_table.h" |
| 27 | #include "intern_table.h" |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 28 | #include "jni_internal.h" |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 29 | #include "large_object_space.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 30 | #include "logging.h" |
| 31 | #include "macros.h" |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 32 | #include "monitor.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 33 | #include "object.h" |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 34 | #include "runtime.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 35 | #include "space.h" |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 36 | #include "timing_logger.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 37 | #include "thread.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 38 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 39 | static const bool kUseMarkStackPrefetch = true; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 40 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 41 | namespace art { |
| 42 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 43 | class SetFingerVisitor { |
| 44 | public: |
| 45 | SetFingerVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 46 | |
| 47 | } |
| 48 | |
| 49 | void operator ()(void* finger) const { |
| 50 | mark_sweep_->SetFinger(reinterpret_cast<Object*>(finger)); |
| 51 | } |
| 52 | |
| 53 | private: |
| 54 | MarkSweep* const mark_sweep_; |
| 55 | }; |
| 56 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 57 | MarkSweep::MarkSweep(ObjectStack* mark_stack) |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 58 | : current_mark_bitmap_(NULL), |
| 59 | mark_stack_(mark_stack), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 60 | heap_(NULL), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 61 | finger_(NULL), |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 62 | immune_begin_(NULL), |
| 63 | immune_end_(NULL), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 64 | soft_reference_list_(NULL), |
| 65 | weak_reference_list_(NULL), |
| 66 | finalizer_reference_list_(NULL), |
| 67 | phantom_reference_list_(NULL), |
| 68 | cleared_reference_list_(NULL), |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 69 | freed_bytes_(0), freed_objects_(0), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 70 | class_count_(0), array_count_(0), other_count_(0) { |
| 71 | DCHECK(mark_stack_ != NULL); |
| 72 | } |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 73 | |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 74 | void MarkSweep::Init() { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 75 | heap_ = Runtime::Current()->GetHeap(); |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 76 | mark_stack_->Reset(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 77 | // TODO: C++0x auto |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 78 | FindDefaultMarkBitmap(); |
buzbee | 0d966cf | 2011-09-08 17:34:58 -0700 | [diff] [blame] | 79 | // TODO: if concurrent, enable card marking in compiler |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 80 | // TODO: check that the mark bitmap is entirely clear. |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 81 | } |
| 82 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 83 | void MarkSweep::FindDefaultMarkBitmap() { |
| 84 | const Spaces& spaces = heap_->GetSpaces(); |
| 85 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 86 | if ((*it)->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect) { |
| 87 | current_mark_bitmap_ = (*it)->GetMarkBitmap(); |
| 88 | CHECK(current_mark_bitmap_ != NULL); |
| 89 | return; |
| 90 | } |
| 91 | } |
| 92 | GetHeap()->DumpSpaces(); |
| 93 | LOG(FATAL) << "Could not find a default mark bitmap"; |
| 94 | } |
| 95 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 96 | inline void MarkSweep::MarkObject0(const Object* obj, bool check_finger) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 97 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 98 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 99 | if (obj >= immune_begin_ && obj < immune_end_) { |
| 100 | DCHECK(IsMarked(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 101 | return; |
| 102 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 103 | |
| 104 | // Try to take advantage of locality of references within a space, failing this find the space |
| 105 | // the hard way. |
Ian Rogers | 506de0c | 2012-09-17 15:39:06 -0700 | [diff] [blame] | 106 | if (UNLIKELY(!current_mark_bitmap_->HasAddress(obj))) { |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 107 | SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetSpaceBitmap(obj); |
| 108 | if (new_bitmap != NULL) { |
| 109 | current_mark_bitmap_ = new_bitmap; |
| 110 | } else { |
| 111 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 112 | SpaceSetMap* large_objects = large_object_space->GetMarkObjects(); |
| 113 | if (!large_objects->Test(obj)) { |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 114 | CHECK(large_object_space->Contains(obj)) << "Attempting to mark object " << obj |
| 115 | << " not in large object space"; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 116 | large_objects->Set(obj); |
| 117 | // Don't need to check finger since large objects never have any object references. |
| 118 | } |
| 119 | // TODO: Improve clarity of control flow in this function? |
| 120 | return; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 121 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 122 | } |
| 123 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 124 | // This object was not previously marked. |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 125 | if (!current_mark_bitmap_->Test(obj)) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 126 | current_mark_bitmap_->Set(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 127 | if (check_finger && obj < finger_) { |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 128 | // Do we need to expand the mark stack? |
| 129 | if (UNLIKELY(mark_stack_->Size() >= mark_stack_->Capacity())) { |
| 130 | std::vector<Object*> temp; |
| 131 | temp.insert(temp.begin(), mark_stack_->Begin(), mark_stack_->End()); |
| 132 | mark_stack_->Resize(mark_stack_->Capacity() * 2); |
| 133 | for (size_t i = 0; i < temp.size(); ++i) { |
| 134 | mark_stack_->PushBack(temp[i]); |
| 135 | } |
| 136 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 137 | // The object must be pushed on to the mark stack. |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 138 | mark_stack_->PushBack(const_cast<Object*>(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 139 | } |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | // Used to mark objects when recursing. Recursion is done by moving |
| 144 | // the finger across the bitmaps in address order and marking child |
| 145 | // objects. Any newly-marked objects whose addresses are lower than |
| 146 | // the finger won't be visited by the bitmap scan, so those objects |
| 147 | // need to be added to the mark stack. |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 148 | void MarkSweep::MarkObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 149 | if (obj != NULL) { |
| 150 | MarkObject0(obj, true); |
| 151 | } |
| 152 | } |
| 153 | |
Elliott Hughes | cf4c6c4 | 2011-09-01 15:16:42 -0700 | [diff] [blame] | 154 | void MarkSweep::MarkObjectVisitor(const Object* root, void* arg) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 155 | DCHECK(root != NULL); |
| 156 | DCHECK(arg != NULL); |
| 157 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 158 | mark_sweep->MarkObject0(root, false); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 159 | } |
| 160 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 161 | void MarkSweep::ReMarkObjectVisitor(const Object* root, void* arg) { |
| 162 | DCHECK(root != NULL); |
| 163 | DCHECK(arg != NULL); |
| 164 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| 165 | mark_sweep->MarkObject0(root, true); |
| 166 | } |
| 167 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 168 | // Marks all objects in the root set. |
| 169 | void MarkSweep::MarkRoots() { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 170 | Runtime::Current()->VisitRoots(MarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 171 | } |
| 172 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 173 | class CheckObjectVisitor { |
| 174 | public: |
| 175 | CheckObjectVisitor(MarkSweep* const mark_sweep) |
| 176 | : mark_sweep_(mark_sweep) { |
| 177 | |
| 178 | } |
| 179 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 180 | void operator ()(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 181 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 182 | Locks::mutator_lock_) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 183 | mark_sweep_->CheckReference(obj, ref, offset, is_static); |
| 184 | } |
| 185 | |
| 186 | private: |
| 187 | MarkSweep* const mark_sweep_; |
| 188 | }; |
| 189 | |
| 190 | void MarkSweep::CheckObject(const Object* obj) { |
| 191 | DCHECK(obj != NULL); |
| 192 | CheckObjectVisitor visitor(this); |
| 193 | VisitObjectReferences(obj, visitor); |
| 194 | } |
| 195 | |
| 196 | void MarkSweep::VerifyImageRootVisitor(Object* root, void* arg) { |
| 197 | DCHECK(root != NULL); |
| 198 | DCHECK(arg != NULL); |
| 199 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 200 | DCHECK(mark_sweep->heap_->GetMarkBitmap()->Test(root)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 201 | mark_sweep->CheckObject(root); |
| 202 | } |
| 203 | |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 204 | void MarkSweep::CopyMarkBits(ContinuousSpace* space) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 205 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 206 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 207 | mark_bitmap->CopyFrom(live_bitmap); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 208 | } |
| 209 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 210 | void MarkSweep::BindLiveToMarkBitmap(ContinuousSpace* space) { |
| 211 | CHECK(space->IsAllocSpace()); |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 212 | DlMallocSpace* alloc_space = space->AsAllocSpace(); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 213 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 214 | SpaceBitmap* mark_bitmap = alloc_space->mark_bitmap_.release(); |
| 215 | GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap); |
| 216 | alloc_space->temp_bitmap_.reset(mark_bitmap); |
| 217 | alloc_space->mark_bitmap_.reset(live_bitmap); |
| 218 | } |
| 219 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 220 | class ScanImageRootVisitor { |
| 221 | public: |
| 222 | ScanImageRootVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 223 | } |
| 224 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 225 | void operator ()(const Object* root) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 226 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 227 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 228 | DCHECK(root != NULL); |
| 229 | mark_sweep_->ScanObject(root); |
| 230 | } |
| 231 | |
| 232 | private: |
| 233 | MarkSweep* const mark_sweep_; |
| 234 | }; |
| 235 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 236 | void MarkSweep::ScanGrayObjects(bool update_finger) { |
| 237 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 238 | CardTable* card_table = heap_->GetCardTable(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 239 | ScanImageRootVisitor image_root_visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 240 | SetFingerVisitor finger_visitor(this); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 241 | // TODO: C++ 0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 242 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 243 | ContinuousSpace* space = *it; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 244 | byte* begin = space->Begin(); |
| 245 | byte* end = space->End(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 246 | // Image spaces are handled properly since live == marked for them. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 247 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 248 | if (update_finger) { |
| 249 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, finger_visitor); |
| 250 | } else { |
| 251 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, IdentityFunctor()); |
| 252 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 253 | } |
| 254 | } |
| 255 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 256 | class CheckBitmapVisitor { |
| 257 | public: |
| 258 | CheckBitmapVisitor(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { |
| 259 | |
| 260 | } |
| 261 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 262 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 263 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 264 | Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 265 | DCHECK(obj != NULL); |
| 266 | mark_sweep_->CheckObject(obj); |
| 267 | } |
| 268 | |
| 269 | private: |
| 270 | MarkSweep* mark_sweep_; |
| 271 | }; |
| 272 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 273 | void MarkSweep::VerifyImageRoots() { |
| 274 | // Verify roots ensures that all the references inside the image space point |
| 275 | // objects which are either in the image space or marked objects in the alloc |
| 276 | // space |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 277 | CheckBitmapVisitor visitor(this); |
| 278 | const Spaces& spaces = heap_->GetSpaces(); |
| 279 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 280 | if ((*it)->IsImageSpace()) { |
| 281 | ImageSpace* space = (*it)->AsImageSpace(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 282 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 283 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 284 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 285 | DCHECK(live_bitmap != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 286 | live_bitmap->VisitMarkedRange(begin, end, visitor, IdentityFunctor()); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 287 | } |
| 288 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 289 | } |
| 290 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 291 | class ScanObjectVisitor { |
| 292 | public: |
| 293 | ScanObjectVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 294 | |
| 295 | } |
| 296 | |
| 297 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 298 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 299 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 300 | mark_sweep_->ScanObject(obj); |
| 301 | } |
| 302 | |
| 303 | private: |
| 304 | MarkSweep* const mark_sweep_; |
| 305 | }; |
| 306 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 307 | // Populates the mark stack based on the set of marked objects and |
| 308 | // recursively marks until the mark stack is emptied. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 309 | void MarkSweep::RecursiveMark(bool partial, TimingLogger& timings) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 310 | // RecursiveMark will build the lists of known instances of the Reference classes. |
| 311 | // See DelayReferenceReferent for details. |
| 312 | CHECK(soft_reference_list_ == NULL); |
| 313 | CHECK(weak_reference_list_ == NULL); |
| 314 | CHECK(finalizer_reference_list_ == NULL); |
| 315 | CHECK(phantom_reference_list_ == NULL); |
| 316 | CHECK(cleared_reference_list_ == NULL); |
| 317 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 318 | const Spaces& spaces = heap_->GetSpaces(); |
| 319 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 320 | SetFingerVisitor set_finger_visitor(this); |
| 321 | ScanObjectVisitor scan_visitor(this); |
| 322 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 323 | ContinuousSpace* space = *it; |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 324 | if (space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect || |
| 325 | (!partial && space->GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect) |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 326 | ) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 327 | current_mark_bitmap_ = space->GetMarkBitmap(); |
| 328 | if (current_mark_bitmap_ == NULL) { |
| 329 | GetHeap()->DumpSpaces(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 330 | LOG(FATAL) << "invalid bitmap"; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 331 | } |
| 332 | // This function does not handle heap end increasing, so we must use the space end. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 333 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 334 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 335 | current_mark_bitmap_->VisitMarkedRange(begin, end, scan_visitor, set_finger_visitor); |
Mathieu Chartier | 7664f5c | 2012-06-08 18:15:32 -0700 | [diff] [blame] | 336 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 337 | } |
| 338 | finger_ = reinterpret_cast<Object*>(~0); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 339 | timings.AddSplit("RecursiveMark"); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 340 | // TODO: tune the frequency of emptying the mark stack |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 341 | ProcessMarkStack(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 342 | timings.AddSplit("ProcessMarkStack"); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 343 | } |
| 344 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 345 | void MarkSweep::RecursiveMarkCards(CardTable* card_table, const std::vector<byte*>& cards, |
| 346 | TimingLogger& timings) { |
| 347 | ScanImageRootVisitor image_root_visitor(this); |
| 348 | SetFingerVisitor finger_visitor(this); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 349 | const size_t card_count = cards.size(); |
| 350 | SpaceBitmap* active_bitmap = NULL; |
| 351 | for (size_t i = 0;i < card_count;) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 352 | Object* start_obj = reinterpret_cast<Object*>(card_table->AddrFromCard(cards[i])); |
| 353 | uintptr_t begin = reinterpret_cast<uintptr_t>(start_obj); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 354 | uintptr_t end = begin + CardTable::kCardSize; |
| 355 | for (++i; reinterpret_cast<uintptr_t>(cards[i]) == end && i < card_count; ++i) { |
| 356 | end += CardTable::kCardSize; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 357 | } |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 358 | if (active_bitmap == NULL || !active_bitmap->HasAddress(start_obj)) { |
| 359 | active_bitmap = heap_->GetMarkBitmap()->GetSpaceBitmap(start_obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 360 | #ifndef NDEBUG |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 361 | if (active_bitmap == NULL) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 362 | GetHeap()->DumpSpaces(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 363 | LOG(FATAL) << "Object " << reinterpret_cast<const void*>(start_obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 364 | } |
| 365 | #endif |
| 366 | } |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 367 | active_bitmap->VisitMarkedRange(begin, end, image_root_visitor, finger_visitor); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 368 | } |
| 369 | timings.AddSplit("RecursiveMarkCards"); |
| 370 | ProcessMarkStack(); |
| 371 | timings.AddSplit("ProcessMarkStack"); |
| 372 | } |
| 373 | |
| 374 | bool MarkSweep::IsMarkedCallback(const Object* object, void* arg) { |
| 375 | return |
| 376 | reinterpret_cast<MarkSweep*>(arg)->IsMarked(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 377 | !reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object); |
| 378 | } |
| 379 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 380 | void MarkSweep::RecursiveMarkDirtyObjects(bool update_finger) { |
| 381 | ScanGrayObjects(update_finger); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 382 | ProcessMarkStack(); |
| 383 | } |
| 384 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 385 | void MarkSweep::ReMarkRoots() { |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 386 | Runtime::Current()->VisitRoots(ReMarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 387 | } |
| 388 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 389 | void MarkSweep::SweepJniWeakGlobals(Heap::IsMarkedTester is_marked, void* arg) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 390 | JavaVMExt* vm = Runtime::Current()->GetJavaVM(); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 391 | MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 392 | IndirectReferenceTable* table = &vm->weak_globals; |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 393 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 394 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 395 | const Object** entry = *it; |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 396 | if (!is_marked(*entry, arg)) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 397 | *entry = kClearedJniWeakGlobal; |
| 398 | } |
| 399 | } |
| 400 | } |
| 401 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 402 | struct ArrayMarkedCheck { |
| 403 | ObjectStack* live_stack; |
| 404 | MarkSweep* mark_sweep; |
| 405 | }; |
| 406 | |
| 407 | // Either marked or not live. |
| 408 | bool MarkSweep::IsMarkedArrayCallback(const Object* object, void* arg) { |
| 409 | ArrayMarkedCheck* array_check = reinterpret_cast<ArrayMarkedCheck*>(arg); |
| 410 | if (array_check->mark_sweep->IsMarked(object)) { |
| 411 | return true; |
| 412 | } |
| 413 | ObjectStack* live_stack = array_check->live_stack; |
| 414 | return std::find(live_stack->Begin(), live_stack->End(), object) == live_stack->End(); |
| 415 | } |
| 416 | |
| 417 | void MarkSweep::SweepSystemWeaksArray(ObjectStack* allocations) { |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 418 | Runtime* runtime = Runtime::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 419 | // The callbacks check |
| 420 | // !is_marked where is_marked is the callback but we want |
| 421 | // !IsMarked && IsLive |
| 422 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 423 | // Or for swapped (IsLive || !IsMarked). |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 424 | |
| 425 | ArrayMarkedCheck visitor; |
| 426 | visitor.live_stack = allocations; |
| 427 | visitor.mark_sweep = this; |
| 428 | runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedArrayCallback, &visitor); |
| 429 | runtime->GetMonitorList()->SweepMonitorList(IsMarkedArrayCallback, &visitor); |
| 430 | SweepJniWeakGlobals(IsMarkedArrayCallback, &visitor); |
| 431 | } |
| 432 | |
| 433 | void MarkSweep::SweepSystemWeaks() { |
| 434 | Runtime* runtime = Runtime::Current(); |
| 435 | // The callbacks check |
| 436 | // !is_marked where is_marked is the callback but we want |
| 437 | // !IsMarked && IsLive |
| 438 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 439 | // Or for swapped (IsLive || !IsMarked). |
| 440 | runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedCallback, this); |
| 441 | runtime->GetMonitorList()->SweepMonitorList(IsMarkedCallback, this); |
| 442 | SweepJniWeakGlobals(IsMarkedCallback, this); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 443 | } |
| 444 | |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 445 | bool MarkSweep::VerifyIsLiveCallback(const Object* obj, void* arg) { |
| 446 | reinterpret_cast<MarkSweep*>(arg)->VerifyIsLive(obj); |
| 447 | // We don't actually want to sweep the object, so lets return "marked" |
| 448 | return true; |
| 449 | } |
| 450 | |
| 451 | void MarkSweep::VerifyIsLive(const Object* obj) { |
| 452 | Heap* heap = GetHeap(); |
| 453 | if (!heap->GetLiveBitmap()->Test(obj)) { |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 454 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 455 | if (!large_object_space->GetLiveObjects()->Test(obj)) { |
| 456 | if (std::find(heap->allocation_stack_->Begin(), heap->allocation_stack_->End(), obj) == |
| 457 | heap->allocation_stack_->End()) { |
| 458 | // Object not found! |
| 459 | heap->DumpSpaces(); |
| 460 | LOG(FATAL) << "Found dead object " << obj; |
| 461 | } |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 462 | } |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | void MarkSweep::VerifySystemWeaks() { |
| 467 | Runtime* runtime = Runtime::Current(); |
| 468 | // Verify system weaks, uses a special IsMarked callback which always returns true. |
| 469 | runtime->GetInternTable()->SweepInternTableWeaks(VerifyIsLiveCallback, this); |
| 470 | runtime->GetMonitorList()->SweepMonitorList(VerifyIsLiveCallback, this); |
| 471 | |
| 472 | JavaVMExt* vm = runtime->GetJavaVM(); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 473 | MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 474 | IndirectReferenceTable* table = &vm->weak_globals; |
| 475 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
| 476 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 477 | const Object** entry = *it; |
| 478 | VerifyIsLive(*entry); |
| 479 | } |
| 480 | } |
| 481 | |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 482 | struct SweepCallbackContext { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 483 | MarkSweep* mark_sweep; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 484 | AllocSpace* space; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 485 | Thread* self; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 486 | }; |
| 487 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 488 | void MarkSweep::SweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 489 | size_t freed_objects = num_ptrs; |
| 490 | size_t freed_bytes = 0; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 491 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 492 | MarkSweep* mark_sweep = context->mark_sweep; |
| 493 | Heap* heap = mark_sweep->GetHeap(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 494 | AllocSpace* space = context->space; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 495 | Thread* self = context->self; |
| 496 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(self); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 497 | // Use a bulk free, that merges consecutive objects before freeing or free per object? |
| 498 | // Documentation suggests better free performance with merging, but this may be at the expensive |
| 499 | // of allocation. |
| 500 | // TODO: investigate performance |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 501 | static const bool kUseFreeList = true; |
| 502 | if (kUseFreeList) { |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 503 | // AllocSpace::FreeList clears the value in ptrs, so perform after clearing the live bit |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 504 | freed_bytes += space->FreeList(self, num_ptrs, ptrs); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 505 | } else { |
| 506 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 507 | Object* obj = static_cast<Object*>(ptrs[i]); |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 508 | freed_bytes += space->Free(self, obj); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 509 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 510 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 511 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 512 | heap->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 513 | mark_sweep->freed_objects_ += freed_objects; |
| 514 | mark_sweep->freed_bytes_ += freed_bytes; |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 515 | } |
| 516 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 517 | void MarkSweep::ZygoteSweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 518 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 519 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(context->self); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 520 | Heap* heap = context->mark_sweep->GetHeap(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 521 | // We don't free any actual memory to avoid dirtying the shared zygote pages. |
| 522 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 523 | Object* obj = static_cast<Object*>(ptrs[i]); |
| 524 | heap->GetLiveBitmap()->Clear(obj); |
| 525 | heap->GetCardTable()->MarkCard(obj); |
| 526 | } |
| 527 | } |
| 528 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 529 | void MarkSweep::SweepArray(TimingLogger& logger, ObjectStack* allocations, bool swap_bitmaps) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 530 | size_t freed_bytes = 0; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 531 | DlMallocSpace* space = heap_->GetAllocSpace(); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 532 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 533 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 534 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
| 535 | // TODO: Fix when sweeping weaks works properly with mutators unpaused + allocation list. |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 536 | SweepSystemWeaksArray(allocations); |
| 537 | logger.AddSplit("SweepSystemWeaks"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 538 | |
| 539 | // Newly allocated objects MUST be in the alloc space and those are the only objects which we are |
| 540 | // going to free. |
| 541 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 542 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 543 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 544 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 545 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 546 | if (swap_bitmaps) { |
| 547 | std::swap(live_bitmap, mark_bitmap); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 548 | std::swap(large_live_objects, large_mark_objects); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 549 | } |
| 550 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 551 | size_t freed_large_objects = 0; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 552 | size_t count = allocations->Size(); |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 553 | Object** objects = const_cast<Object**>(allocations->Begin()); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 554 | Object** out = objects; |
| 555 | |
| 556 | // Empty the allocation stack. |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 557 | Thread* self = Thread::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 558 | for (size_t i = 0;i < count;++i) { |
| 559 | Object* obj = objects[i]; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 560 | // There should only be objects in the AllocSpace/LargeObjectSpace in the allocation stack. |
| 561 | if (LIKELY(mark_bitmap->HasAddress(obj))) { |
| 562 | if (!mark_bitmap->Test(obj)) { |
| 563 | // Don't bother un-marking since we clear the mark bitmap anyways. |
| 564 | *(out++) = obj; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 565 | } |
| 566 | } else if (!large_mark_objects->Test(obj)) { |
| 567 | ++freed_large_objects; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 568 | freed_bytes += large_object_space->Free(self, obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 569 | } |
| 570 | } |
| 571 | logger.AddSplit("Process allocation stack"); |
| 572 | |
| 573 | size_t freed_objects = out - objects; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 574 | freed_bytes += space->FreeList(self, freed_objects, objects); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 575 | VLOG(heap) << "Freed " << freed_objects << "/" << count |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 576 | << " objects with size " << PrettySize(freed_bytes); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 577 | heap_->RecordFree(freed_objects + freed_large_objects, freed_bytes); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 578 | freed_objects_ += freed_objects; |
| 579 | freed_bytes_ += freed_bytes; |
| 580 | logger.AddSplit("FreeList"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 581 | allocations->Reset(); |
| 582 | logger.AddSplit("Reset stack"); |
| 583 | } |
| 584 | |
| 585 | void MarkSweep::Sweep(bool partial, bool swap_bitmaps) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 586 | DCHECK(mark_stack_->IsEmpty()); |
| 587 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 588 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 589 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 590 | SweepSystemWeaks(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 591 | |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 592 | const Spaces& spaces = heap_->GetSpaces(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 593 | SweepCallbackContext scc; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 594 | scc.mark_sweep = this; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 595 | scc.self = Thread::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 596 | // TODO: C++0x auto |
| 597 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 598 | ContinuousSpace* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 599 | if ( |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 600 | space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect || |
| 601 | (!partial && space->GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect) |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 602 | ) { |
| 603 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 604 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 605 | scc.space = space->AsAllocSpace(); |
| 606 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 607 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | fd678be | 2012-08-30 14:50:54 -0700 | [diff] [blame] | 608 | if (swap_bitmaps) { |
| 609 | std::swap(live_bitmap, mark_bitmap); |
| 610 | } |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 611 | if (space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 612 | // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 613 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 614 | &SweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 615 | } else { |
| 616 | // Zygote sweep takes care of dirtying cards and clearing live bits, does not free actual memory. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 617 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 618 | &ZygoteSweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 619 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 620 | } |
| 621 | } |
| 622 | } |
| 623 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 624 | void MarkSweep::SweepLargeObjects(bool swap_bitmaps) { |
| 625 | // Sweep large objects |
| 626 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 627 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 628 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
| 629 | if (swap_bitmaps) { |
| 630 | std::swap(large_live_objects, large_mark_objects); |
| 631 | } |
| 632 | SpaceSetMap::Objects& live_objects = large_live_objects->GetObjects(); |
| 633 | // O(n*log(n)) but hopefully there are not too many large objects. |
| 634 | size_t freed_objects = 0; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 635 | size_t freed_bytes = 0; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 636 | // TODO: C++0x |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 637 | Thread* self = Thread::Current(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 638 | for (SpaceSetMap::Objects::iterator it = live_objects.begin(); it != live_objects.end(); ++it) { |
| 639 | if (!large_mark_objects->Test(*it)) { |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 640 | freed_bytes += large_object_space->Free(self, const_cast<Object*>(*it)); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 641 | ++freed_objects; |
| 642 | } |
| 643 | } |
| 644 | freed_objects_ += freed_objects; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 645 | freed_bytes_ += freed_bytes; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 646 | // Large objects don't count towards bytes_allocated. |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 647 | GetHeap()->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 648 | } |
| 649 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 650 | // Scans instance fields. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 651 | inline void MarkSweep::ScanInstanceFields(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 652 | DCHECK(obj != NULL); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 653 | Class* klass = obj->GetClass(); |
| 654 | DCHECK(klass != NULL); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 655 | ScanFields(obj, klass->GetReferenceInstanceOffsets(), false); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 656 | } |
| 657 | |
| 658 | // Scans static storage on a Class. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 659 | inline void MarkSweep::ScanStaticFields(const Class* klass) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 660 | DCHECK(klass != NULL); |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 661 | ScanFields(klass, klass->GetReferenceStaticOffsets(), true); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 662 | } |
| 663 | |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 664 | inline void MarkSweep::ScanFields(const Object* obj, uint32_t ref_offsets, bool is_static) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 665 | if (ref_offsets != CLASS_WALK_SUPER) { |
| 666 | // Found a reference offset bitmap. Mark the specified offsets. |
| 667 | while (ref_offsets != 0) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 668 | const size_t right_shift = CLZ(ref_offsets); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 669 | MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift); |
| 670 | const Object* ref = obj->GetFieldObject<const Object*>(byte_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 671 | MarkObject(ref); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 672 | ref_offsets ^= CLASS_HIGH_BIT >> right_shift; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 673 | } |
| 674 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 675 | // There is no reference offset bitmap. In the non-static case, |
| 676 | // walk up the class inheritance hierarchy and find reference |
| 677 | // offsets the hard way. In the static case, just consider this |
| 678 | // class. |
| 679 | for (const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 680 | klass != NULL; |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 681 | klass = is_static ? NULL : klass->GetSuperClass()) { |
| 682 | size_t num_reference_fields = (is_static |
| 683 | ? klass->NumReferenceStaticFields() |
| 684 | : klass->NumReferenceInstanceFields()); |
| 685 | for (size_t i = 0; i < num_reference_fields; ++i) { |
| 686 | Field* field = (is_static |
| 687 | ? klass->GetStaticField(i) |
| 688 | : klass->GetInstanceField(i)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 689 | MemberOffset field_offset = field->GetOffset(); |
| 690 | const Object* ref = obj->GetFieldObject<const Object*>(field_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 691 | MarkObject(ref); |
| 692 | } |
| 693 | } |
| 694 | } |
| 695 | } |
| 696 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 697 | void MarkSweep::CheckReference(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) { |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 698 | const Spaces& spaces = heap_->GetSpaces(); |
| 699 | // TODO: C++0x auto |
| 700 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
| 701 | if ((*cur)->IsAllocSpace() && (*cur)->Contains(ref)) { |
| 702 | DCHECK(IsMarked(obj)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 703 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 704 | bool is_marked = IsMarked(ref); |
| 705 | if (!is_marked) { |
| 706 | LOG(INFO) << **cur; |
| 707 | LOG(WARNING) << (is_static ? "Static ref'" : "Instance ref'") << PrettyTypeOf(ref) |
| 708 | << "' (" << reinterpret_cast<const void*>(ref) << ") in '" << PrettyTypeOf(obj) |
| 709 | << "' (" << reinterpret_cast<const void*>(obj) << ") at offset " |
| 710 | << reinterpret_cast<void*>(offset.Int32Value()) << " wasn't marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 711 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 712 | const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
| 713 | DCHECK(klass != NULL); |
| 714 | const ObjectArray<Field>* fields = is_static ? klass->GetSFields() : klass->GetIFields(); |
| 715 | DCHECK(fields != NULL); |
| 716 | bool found = false; |
| 717 | for (int32_t i = 0; i < fields->GetLength(); ++i) { |
| 718 | const Field* cur = fields->Get(i); |
| 719 | if (cur->GetOffset().Int32Value() == offset.Int32Value()) { |
| 720 | LOG(WARNING) << "Field referencing the alloc space was " << PrettyField(cur); |
| 721 | found = true; |
| 722 | break; |
| 723 | } |
| 724 | } |
| 725 | if (!found) { |
| 726 | LOG(WARNING) << "Could not find field in object alloc space with offset " << offset.Int32Value(); |
| 727 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 728 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 729 | bool obj_marked = heap_->GetCardTable()->IsDirty(obj); |
| 730 | if (!obj_marked) { |
| 731 | LOG(WARNING) << "Object '" << PrettyTypeOf(obj) << "' " |
| 732 | << "(" << reinterpret_cast<const void*>(obj) << ") contains references to " |
| 733 | << "the alloc space, but wasn't card marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 734 | } |
| 735 | } |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 736 | } |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 737 | break; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 738 | } |
| 739 | } |
| 740 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 741 | // Scans the header, static field references, and interface pointers |
| 742 | // of a class object. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 743 | inline void MarkSweep::ScanClass(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 744 | #ifndef NDEBUG |
| 745 | ++class_count_; |
| 746 | #endif |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 747 | ScanInstanceFields(obj); |
Brian Carlstrom | 40381fb | 2011-10-19 14:13:40 -0700 | [diff] [blame] | 748 | ScanStaticFields(obj->AsClass()); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 749 | } |
| 750 | |
| 751 | // Scans the header of all array objects. If the array object is |
| 752 | // specialized to a reference type, scans the array data as well. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 753 | inline void MarkSweep::ScanArray(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 754 | #ifndef NDEBUG |
| 755 | ++array_count_; |
| 756 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 757 | MarkObject(obj->GetClass()); |
| 758 | if (obj->IsObjectArray()) { |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 759 | const ObjectArray<Object>* array = obj->AsObjectArray<Object>(); |
Elliott Hughes | d8ddfd5 | 2011-08-15 14:32:53 -0700 | [diff] [blame] | 760 | for (int32_t i = 0; i < array->GetLength(); ++i) { |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 761 | const Object* element = array->GetWithoutChecks(i); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 762 | MarkObject(element); |
| 763 | } |
| 764 | } |
| 765 | } |
| 766 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 767 | // Process the "referent" field in a java.lang.ref.Reference. If the |
| 768 | // referent has not yet been marked, put it on the appropriate list in |
| 769 | // the gcHeap for later processing. |
| 770 | void MarkSweep::DelayReferenceReferent(Object* obj) { |
| 771 | DCHECK(obj != NULL); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 772 | Class* klass = obj->GetClass(); |
| 773 | DCHECK(klass != NULL); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 774 | DCHECK(klass->IsReferenceClass()); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 775 | Object* pending = obj->GetFieldObject<Object*>(heap_->GetReferencePendingNextOffset(), false); |
| 776 | Object* referent = heap_->GetReferenceReferent(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 777 | if (pending == NULL && referent != NULL && !IsMarked(referent)) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 778 | Object** list = NULL; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 779 | if (klass->IsSoftReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 780 | list = &soft_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 781 | } else if (klass->IsWeakReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 782 | list = &weak_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 783 | } else if (klass->IsFinalizerReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 784 | list = &finalizer_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 785 | } else if (klass->IsPhantomReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 786 | list = &phantom_reference_list_; |
| 787 | } |
Brian Carlstrom | 0796af0 | 2011-10-12 14:31:45 -0700 | [diff] [blame] | 788 | DCHECK(list != NULL) << PrettyClass(klass) << " " << std::hex << klass->GetAccessFlags(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 789 | heap_->EnqueuePendingReference(obj, list); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 790 | } |
| 791 | } |
| 792 | |
| 793 | // Scans the header and field references of a data object. If the |
| 794 | // scanned object is a reference subclass, it is scheduled for later |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 795 | // processing. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 796 | inline void MarkSweep::ScanOther(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 797 | #ifndef NDEBUG |
| 798 | ++other_count_; |
| 799 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 800 | ScanInstanceFields(obj); |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 801 | if (obj->GetClass()->IsReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 802 | DelayReferenceReferent(const_cast<Object*>(obj)); |
| 803 | } |
| 804 | } |
| 805 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 806 | void MarkSweep::ScanRoot(const Object* obj) { |
| 807 | ScanObject(obj); |
| 808 | } |
| 809 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 810 | // Scans an object reference. Determines the type of the reference |
| 811 | // and dispatches to a specialized scanning routine. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 812 | void MarkSweep::ScanObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 813 | DCHECK(obj != NULL); |
| 814 | DCHECK(obj->GetClass() != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 815 | #ifndef NDEBUG |
| 816 | if (!IsMarked(obj)) { |
| 817 | heap_->DumpSpaces(); |
| 818 | LOG(FATAL) << "Scanning unmarked object " << reinterpret_cast<const void*>(obj); |
| 819 | } |
| 820 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 821 | if (obj->IsClass()) { |
| 822 | ScanClass(obj); |
Brian Carlstrom | b63ec39 | 2011-08-27 17:38:27 -0700 | [diff] [blame] | 823 | } else if (obj->IsArrayInstance()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 824 | ScanArray(obj); |
| 825 | } else { |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 826 | ScanOther(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 827 | } |
| 828 | } |
| 829 | |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 830 | // Scan anything that's on the mark stack. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 831 | void MarkSweep::ProcessMarkStack() { |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 832 | if (kUseMarkStackPrefetch) { |
| 833 | const size_t fifo_size = 4; |
| 834 | const size_t fifo_mask = fifo_size - 1; |
| 835 | const Object* fifo[fifo_size]; |
| 836 | for (size_t i = 0;i < fifo_size;++i) { |
| 837 | fifo[i] = NULL; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 838 | } |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 839 | size_t fifo_pos = 0; |
| 840 | size_t fifo_count = 0; |
| 841 | for (;;) { |
| 842 | const Object* obj = fifo[fifo_pos & fifo_mask]; |
| 843 | if (obj != NULL) { |
| 844 | ScanObject(obj); |
| 845 | fifo[fifo_pos & fifo_mask] = NULL; |
| 846 | --fifo_count; |
| 847 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 848 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 849 | if (!mark_stack_->IsEmpty()) { |
| 850 | const Object* obj = mark_stack_->PopBack(); |
| 851 | DCHECK(obj != NULL); |
| 852 | fifo[fifo_pos & fifo_mask] = obj; |
| 853 | __builtin_prefetch(obj); |
| 854 | fifo_count++; |
| 855 | } |
| 856 | fifo_pos++; |
| 857 | |
| 858 | if (!fifo_count) { |
| 859 | CHECK(mark_stack_->IsEmpty()) << mark_stack_->Size(); |
| 860 | break; |
| 861 | } |
| 862 | } |
| 863 | } else { |
| 864 | while (!mark_stack_->IsEmpty()) { |
| 865 | const Object* obj = mark_stack_->PopBack(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 866 | DCHECK(obj != NULL); |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 867 | ScanObject(obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 868 | } |
| 869 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 870 | } |
| 871 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 872 | // Walks the reference list marking any references subject to the |
| 873 | // reference clearing policy. References with a black referent are |
| 874 | // removed from the list. References with white referents biased |
| 875 | // toward saving are blackened and also removed from the list. |
| 876 | void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| 877 | DCHECK(list != NULL); |
| 878 | Object* clear = NULL; |
| 879 | size_t counter = 0; |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 880 | |
| 881 | DCHECK(mark_stack_->IsEmpty()); |
| 882 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 883 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 884 | Object* ref = heap_->DequeuePendingReference(list); |
| 885 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 886 | if (referent == NULL) { |
| 887 | // Referent was cleared by the user during marking. |
| 888 | continue; |
| 889 | } |
| 890 | bool is_marked = IsMarked(referent); |
| 891 | if (!is_marked && ((++counter) & 1)) { |
| 892 | // Referent is white and biased toward saving, mark it. |
| 893 | MarkObject(referent); |
| 894 | is_marked = true; |
| 895 | } |
| 896 | if (!is_marked) { |
| 897 | // Referent is white, queue it for clearing. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 898 | heap_->EnqueuePendingReference(ref, &clear); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 899 | } |
| 900 | } |
| 901 | *list = clear; |
| 902 | // Restart the mark with the newly black references added to the |
| 903 | // root set. |
| 904 | ProcessMarkStack(); |
| 905 | } |
| 906 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 907 | inline bool MarkSweep::IsMarked(const Object* object) const |
| 908 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { |
| 909 | if (object >= immune_begin_ && object < immune_end_) { |
| 910 | return true; |
| 911 | } |
| 912 | DCHECK(current_mark_bitmap_ != NULL); |
| 913 | if (current_mark_bitmap_->HasAddress(object)) { |
| 914 | return current_mark_bitmap_->Test(object); |
| 915 | } |
| 916 | return heap_->GetMarkBitmap()->Test(object); |
| 917 | } |
| 918 | |
| 919 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 920 | // Unlink the reference list clearing references objects with white |
| 921 | // referents. Cleared references registered to a reference queue are |
| 922 | // scheduled for appending by the heap worker thread. |
| 923 | void MarkSweep::ClearWhiteReferences(Object** list) { |
| 924 | DCHECK(list != NULL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 925 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 926 | Object* ref = heap_->DequeuePendingReference(list); |
| 927 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 928 | if (referent != NULL && !IsMarked(referent)) { |
| 929 | // Referent is white, clear it. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 930 | heap_->ClearReferenceReferent(ref); |
| 931 | if (heap_->IsEnqueuable(ref)) { |
| 932 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 933 | } |
| 934 | } |
| 935 | } |
| 936 | DCHECK(*list == NULL); |
| 937 | } |
| 938 | |
| 939 | // Enqueues finalizer references with white referents. White |
| 940 | // referents are blackened, moved to the zombie field, and the |
| 941 | // referent field is cleared. |
| 942 | void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| 943 | DCHECK(list != NULL); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 944 | MemberOffset zombie_offset = heap_->GetFinalizerReferenceZombieOffset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 945 | bool has_enqueued = false; |
| 946 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 947 | Object* ref = heap_->DequeuePendingReference(list); |
| 948 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 949 | if (referent != NULL && !IsMarked(referent)) { |
| 950 | MarkObject(referent); |
| 951 | // If the referent is non-null the reference must queuable. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 952 | DCHECK(heap_->IsEnqueuable(ref)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 953 | ref->SetFieldObject(zombie_offset, referent, false); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 954 | heap_->ClearReferenceReferent(ref); |
| 955 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 956 | has_enqueued = true; |
| 957 | } |
| 958 | } |
| 959 | if (has_enqueued) { |
| 960 | ProcessMarkStack(); |
| 961 | } |
| 962 | DCHECK(*list == NULL); |
| 963 | } |
| 964 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 965 | // Process reference class instances and schedule finalizations. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 966 | void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| 967 | Object** weak_references, |
| 968 | Object** finalizer_references, |
| 969 | Object** phantom_references) { |
| 970 | DCHECK(soft_references != NULL); |
| 971 | DCHECK(weak_references != NULL); |
| 972 | DCHECK(finalizer_references != NULL); |
| 973 | DCHECK(phantom_references != NULL); |
| 974 | |
| 975 | // Unless we are in the zygote or required to clear soft references |
| 976 | // with white references, preserve some white referents. |
Ian Rogers | 2945e24 | 2012-06-03 14:45:16 -0700 | [diff] [blame] | 977 | if (!clear_soft && !Runtime::Current()->IsZygote()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 978 | PreserveSomeSoftReferences(soft_references); |
| 979 | } |
| 980 | |
| 981 | // Clear all remaining soft and weak references with white |
| 982 | // referents. |
| 983 | ClearWhiteReferences(soft_references); |
| 984 | ClearWhiteReferences(weak_references); |
| 985 | |
| 986 | // Preserve all white objects with finalize methods and schedule |
| 987 | // them for finalization. |
| 988 | EnqueueFinalizerReferences(finalizer_references); |
| 989 | |
| 990 | // Clear all f-reachable soft and weak references with white |
| 991 | // referents. |
| 992 | ClearWhiteReferences(soft_references); |
| 993 | ClearWhiteReferences(weak_references); |
| 994 | |
| 995 | // Clear all phantom references with white referents. |
| 996 | ClearWhiteReferences(phantom_references); |
| 997 | |
| 998 | // At this point all reference lists should be empty. |
| 999 | DCHECK(*soft_references == NULL); |
| 1000 | DCHECK(*weak_references == NULL); |
| 1001 | DCHECK(*finalizer_references == NULL); |
| 1002 | DCHECK(*phantom_references == NULL); |
| 1003 | } |
| 1004 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1005 | void MarkSweep::UnBindBitmaps() { |
| 1006 | const Spaces& spaces = heap_->GetSpaces(); |
| 1007 | // TODO: C++0x auto |
| 1008 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 1009 | Space* space = *it; |
| 1010 | if (space->IsAllocSpace()) { |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame^] | 1011 | DlMallocSpace* alloc_space = space->AsAllocSpace(); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1012 | if (alloc_space->temp_bitmap_.get() != NULL) { |
| 1013 | // At this point, the temp_bitmap holds our old mark bitmap. |
| 1014 | SpaceBitmap* new_bitmap = alloc_space->temp_bitmap_.release(); |
| 1015 | GetHeap()->GetMarkBitmap()->ReplaceBitmap(alloc_space->mark_bitmap_.get(), new_bitmap); |
| 1016 | CHECK_EQ(alloc_space->mark_bitmap_.release(), alloc_space->live_bitmap_.get()); |
| 1017 | alloc_space->mark_bitmap_.reset(new_bitmap); |
| 1018 | DCHECK(alloc_space->temp_bitmap_.get() == NULL); |
| 1019 | } |
| 1020 | } |
| 1021 | } |
| 1022 | } |
| 1023 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1024 | MarkSweep::~MarkSweep() { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 1025 | #ifndef NDEBUG |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 1026 | VLOG(heap) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_ << " other=" << other_count_; |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 1027 | #endif |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1028 | // Ensure that the mark stack is empty. |
| 1029 | CHECK(mark_stack_->IsEmpty()); |
| 1030 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1031 | // Clear all of the alloc spaces' mark bitmaps. |
| 1032 | const Spaces& spaces = heap_->GetSpaces(); |
| 1033 | // TODO: C++0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1034 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1035 | ContinuousSpace* space = *it; |
| 1036 | if (space->GetGcRetentionPolicy() != kGcRetentionPolicyNeverCollect) { |
| 1037 | space->GetMarkBitmap()->Clear(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1038 | } |
| 1039 | } |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 1040 | mark_stack_->Reset(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1041 | |
| 1042 | // Reset the marked large objects. |
| 1043 | LargeObjectSpace* large_objects = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1044 | large_objects->GetMarkObjects()->Clear(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1045 | } |
| 1046 | |
| 1047 | } // namespace art |